催化学报 ›› 2012, Vol. 33 ›› Issue (3): 570-575.DOI: 10.3724/SP.J.1088.2012.10965

• 研究论文 • 上一篇    下一篇

双功能 WC/HZSM-5催化剂上正己烷芳构化反应性能

施梅勤 a, 陈宁宁, 马淳安 b, 李瑛, 魏爱平   

  1. 浙江工业大学化学工程与材料学院, 绿色化学合成技术国家重点实验室培育基地, 科技部能源材料及应用国际科技合作基地, 浙江杭州 310032
  • 收稿日期:2011-09-10 修回日期:2011-12-02 出版日期:2012-03-15 发布日期:2015-07-27

Catalytic Performance of Bi-functional WC/HZSM-5 Catalysts for n-Hexane Aromatization

SHI Meiqina, CHEN Ningning, MA Chun’anb, LI Ying, WEI Aiping   

  1. State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, College of Chemical Engineering and Materials Science, Zhejiang University of Technology, International Sci & Tech Cooperation Base of Energy Materials and Application, Hangzhou 310032, Zhejiang, China
  • Received:2011-09-10 Revised:2011-12-02 Online:2012-03-15 Published:2015-07-27

摘要: 以 HZSM-5 (SiO2/Al2O3 = 38) 为载体, 偏钨酸铵为钨源制备了双功能催化剂 WC/HZSM-5, 考察了其催化正己烷芳构化反应性能, 并采用 X 射线衍射、扫描电子显微镜、X 射线能量散射谱和程序升温氨脱附等手段对催化剂进行了表征, 探讨了制备方法和 WC 含量对 WC/HZSM-5 催化剂性能的影响. 结果表明, 采用原位还原碳化法制备的 WC/HZSM-5(RC) 催化剂上正己烷芳构化反应性能优于浸渍法制备的 WC/HZSM-5(IP). 5%WC/HZSM-5(RC) 样品在反应初始阶段芳烃选择性为 10.28%, 而 HZSM-5 上的仅为 2.56%. WC/HZSM-5(RC) 催化剂上反应产物中轻质芳烃 (苯、甲苯和二甲苯) 含量增加, 重质芳烃 C9+含量降低, 其催化性能优于 Pt/HZSM-5 催化剂. 产物分布的变化可能是由于 WC 与分子筛间的协同作用所致.

关键词: HZSM-5 分子筛, 碳化钨, 负载型催化剂, 正己烷, 芳构化, 裂解

Abstract: Bi-functional tungsten carbide (WC) supported on HZSM-5 (WC/HZSM-5) catalyst samples were prepared and studied in n-hexane aromatization. Two series of catalyst samples with varying WC loadings were synthesized by in-situ reduction-carbonization (WC/HZSM-5(RC)) and impregnation methods (WC/HZSM-5(IP)). The catalyst samples were characterized by NH3 temperature-programmed desorption, X-ray diffraction, and scanning electron microscopy combined with energy dispersive spectroscopy. The results showed that WC/HZSM-5(RC) has much higher catalytic activity than WC/HZSM-5(IP). The aromatic selectivity on 5%WC/HZSM-5(RC) was 10.28%, which was much higher than that of HZSM-5 (2.56%). The aromatics (benzene, toluene, and xylene) content in liquid products was 85.07%, much higher than that of HZSM-5 (67.71%). These results are interpreted by the bi-functional mechanism due to the synergistic action between the HZSM-5 and WC.

Key words: HZSM-5 zeolite, tungsten carbide, supported catalyst, n-hexane, aromatization, cracking